In general, a bill processing apparatus, which is one of the embodiments of the paper sheet apparatus, is incorporated into a service device such as a game medium rental machine installed in a game hall, a vending machine or a ticket-vending machine installed in a public space, or the like which identifies the validity of a bill inserted from a bill insertion slot by a user and provides various types of products and services in accordance with a value of the bill having been judged as valid. Such a bill processing apparatus includes a bill conveyance mechanism that conveys a bill inserted into a bill insertion slot, and a bill identification part that judges the validity of the bill (or also called authenticity judgment) to be conveyed.
In the bill processing apparatus described above, after a bill is inserted from the bill insertion slot, it is necessary to prevent the inserted bill from being drawn out for the purpose of fraudulent activity. For example, Patent Document 1 discloses a configuration in which a tongue piece projecting from the frame is provided to a portion on the front side of a discharge slot in a bill processing apparatus in which a bill inserted into a bill insertion slot is conveyed to the discharge slot by a roller, or the like. This tongue piece is configured to rise up so as to be inclined on the surface of a traveling route through which a bill moves, that allows the bill to move in its traveling direction along the inclined surface, and when the bill moves in its opposite direction (moves in a drawing-out direction), the bill comes to be caught by the tongue piece.    [Patent Reference 1] Japanese unexamined utility model application publication No. S63-89181